Ch 8: Special Senses THE EYE AND VISION Name (in ink)
1. Identify each of the eye muscles indicated by leader lines in Figure 8-1. Color code and color each muscle a different color. Then, in the blanks below, indicate the eye movement caused by each muscle.
⃝� 1. Superior rectus � 4. Lateral rectus
⃝� 2. Inferior rectus � 5. Medial rectus
⃝� 3. Superior oblique � 6. Inferior oblique
Figure 8-1
Optic nerve
Cornea
2. Three main accessory eye structures contribute to the formation of tears and/or aid in lubricating the eyeball. In the table, name each structure and then name its major secretory product. Indicate which of the secretions has antibacterial properties by circling that response.
Accessory eye structures Secretory product
1.
2.
3.
3. Using key choices, identify the parts of the eye described in the following statements.
⃝� A. Aqueous humor � F. Fovea centralis � K. Sclera (fibrous tunic)
⃝� B. Canal of Schlemm � G. Iris � L. Suspensory ligament
⃝� C. Choroid coat � H. Lens � M. Vitreous humor
⃝� D. Ciliary body � I. Optic disk N. Photoreceptors
⃝� E. Cornea � J. Retina
____________________ 1. Receptors for vision, respond to light: (1) rods - detect shades of gray, (2) cones - detect color
____________________ 2. Attaches the lens to the ciliary body
____________________ 3. Fluid that provides nutrients to the lens and cornea
____________________ 4. The "white" outer layer of the eye
____________________ 5. Area of retina that lacks photoreceptors (blind spot)
____________________ 6. Contains muscle that controls the shape of the lens
____________________ 7. Nutritive (vascular) tunic of the eye
____________________ 8. Drains the aqueous humor of the eye
____________________ 9. Sensory tunic, containing the rods and cones
____________________ 10. Gel-like substance that helps to reinforce the eyeball
____________________ 11. Heavily pigmented tunic that prevents light scattering within the eye
____________________ 12. 13. Smooth muscle structures (intrinsic eye muscles)
____________________ 14. Area of acute (sharp) or discriminatory vision (central vision)
____________________ 15. 16. Refractory media of the eye (#15-18 in order)
____________________ 17. 18.
____________________ 19. Clear, anterior part of the sclera through which light enters the eye
____________________ 20. Pigmented "diaphragm" of the eye (controls the amount of light entering)
____________________ 21. Flexible structure, changes shape to focus.
4. In the following table circle the correct word under the vertical headings that describes events occurring within the eye during close and distant vision.
Vision Ciliary Muscle Lens convexity Degree of light refraction
1. Distant Relaxed Contracted Increased Decreased Increased Decreased
2. Close Relaxed Contracted Increased Decreased Increased Decreased
5. Using the key choice terms given in Exercise 3, identify the structures indicated by leader lines on the diagram of the eye in Figure 8-2. Select different colors for all structures provided with a color-coding circle and then use them to color the coding circles and corresponding structures in the figure.
eyelid
eyelid
Figure 8-2
6. Complete the following statements by inserting your responses in the answer blanks.
____________________ 1. There are varieties of cones.
____________________ 2. One type responds most vigorously to light,
____________________ 3. another to light,
____________________ 4. and still another to light.
____________________ 5. The ability to see intermediate colors such as purple results from the fact that more than one cone type is being stimulated .
____________________ 6. Lack of all color receptors results in .
____________________ 7. Because this condition is sex linked, it occurs more commonly in .
____________________ 8. Black and white, or dim light, vision is a function of the .
7. Match the terms provided in Column B with the appropriate descriptions in Column A. Insert the correct letter response or corresponding term in the answer blanks.
Column A Column B____________________ 1. Light bending
____________________ 2. Ability to focus for close vision (under 20 feet)
____________________ 3. Normal vision
____________________ 4. Inability to focus well on close objects; farsightedness
____________________ 5. Reflex-constriction of pupils when exposed to bright light
____________________ 6. Clouding of the lens, resulting in loss of sight
____________________ 7. Nearsightedness
____________________ 8. Blurred vision, resulting from unequal curvatures of the lens or cornea
____________________ 9. Medial movement of the eyes during focusing on close objects
____________________ 10. Reflex constriction of the pupils when viewing close objects
____________________ 11. Inflammation of the membrane that lines the eyelids and covers outer surface of the eye
____________________ 12. Lack of cones
A. Accommodation
B. Accommodation pupillary reflex
C. Astigmatism
D. Cataract
E. Convergence
F. Emmetropia
G. Hyperopia
H. Myopia
I. Photopupillary reflex
J. Refraction
K. Color blindness
L. Conjunctivitis
8. The intrinsic eye muscles are under the control of which division of the nervous system?
1. Autonomic nervous system 2. Somatic nervous system
THE EAR: HEARING AND BALANCE
9. Figure 8-3 is a diagram of the ear. Use anatomical terms (as needed) from key choices in Exercise 11 to correctly identify all structures in the figure provided with leader lines. Color all external ear structures yellow; color the ossicles red ; color the equilibrium areas of the inner ear green ; and color the inner ear structures involved with hearing blue .
10. Sound waves hitting the eardrum set it into vibration. Trace the pathway through which vibrations and fluid currents travel to finally stimulate the hair cells in the organ of Corti. Name the appropriate ear structures in their correct sequence and insert your responses in the answer blanks.
Eardrum → → →
Figure 8-3
→ Oval window → →
→ → Hair cells (mechanoreceptors)
11. Using key choices, select the terms that apply to the following descriptions. Place letters in the blanks.
Key Choices
A. Incus E. External auditory canal I. Cochlear nerve M. Tympanic membrane
B. Auditory tube F. Malleus J. Vestibular nerve N. Vestibule
C. Cochlea G. Oval Window K. Semicircular canals O. Mechanoreceptors
D. Endolymph H. Perilymph L. Stapes P. Ceruminous glands
1. 2. 3. Structures composing the outer ear
4. 5. 6. Collectively called the ossicles – bones of the middle ear
7. 8. 9. Structures composing the bony or osseous labyrinth (inner ear)
10. Ear structure involved with hearing
11. 12. Structures that contain receptors for the sense of equilibrium
13. Middle ear structure that opens to equalize pressure in the middle ear with atmospheric pressure
14. Vibrates as sound waves hit it; transmits the vibrations to the ossicles
15. Contains the organ of Corti – structure for hearing
16. Tube that connects the nasopharynx (throat posterior to the nasal cavity) and the middle ear
_______ 17. Produce cerumen (earwax)
________ 18. Transmits the vibrations from the stapes to the fluid in the inner ear (perilymph)
_______ 19. Receptors of the inner ear that respond to vibrations
20. Fluid within the membranous labyrinth that bathes the sensory receptors of the inner ear
21. Fluid contained within the osseous labyrinth, which surrounds the membranous labyrinth
22. Structure that transmits impulses to the auditory cortex in the temporal lobe for interpretation
23. Structure that transmits impulses to the cerebellum for interpretation of head position and body movement
Q. Pinna (Auricle)
12. Complete the following statements on the functioning of the static and dynamic equilibrium receptors by inserting the letter or term from the key choices in the answer blanks.
Key Choices
A. Angular/rotatory E. Gravity I. Semicircular canals
B. Hair cells F. Perilymp J. Static
C. Dynamic G. Proprioceptors K. Otoliths
D. Endolymph H. Vestibule L . Photoreceptors
____________________ 1. The type of equilibrium involved with motion is equilibrium.
____________________ 2. The receptors that respond to movements are found in the .
____________________ 3. These receptors respond to changes in movements of the head.
____________________ 4. When motion begins, the fluid (covering hair cells) lags behind, which excites the hair cells.
____________________ 5. When the motion stops suddenly, the fluid flows in the opposite direction and again stimulates the_____.
____________________ 6. The type of equilibrium that provides information on which way is up or down and helps us keep our head erect is equilibrium.
____________________ 7. These receptors that report on the position of the head are found in the .
____________________ 8. Tiny stones found in a gel overlying the hair cells roll in response to the pull of . As they roll, the gel moves and tugs on the hair cells, exciting them.
____________________ 9. These stones are called .
____________________ 10. Besides the equilibrium receptors of the inner ear, receptors in muscles and tendons called also send information to the brain about body position.
____________________ 11. Additionally, receptors for vision called are also important in helping to maintain equilibrium by informing the brain of body position in the environment.
CHEMICAL SENSES: SMELL AND TASTE
13. Complete the following statements by inserting your responses in the answer blanks.
____________________ 1. Sensory receptors for smell and taste that are activated by chemicals are .
____________________ 2. The specific receptors for the sense of smell stimulated by chemicals dissolved in the mucus of the nasal cavity are .
____________________ 3. The specific receptors for smell are located in the of the nasal passages.
____________________ 4. The act of increases the sensation, because it brings more air into contact with the receptors.
____________________ 5. The receptors for taste that respond to chemicals dissolved in saliva are .
____________________ 6. These receptors are found in cluster-like areas called .
____________________ 7. The four basic taste sensations are ,
____________________ 8.
____________________ 9.
____________________ 10.
____________________ 11. The most protective receptors are thought to be those that respond to substances.
____________________ 12. When nasal passages are congested, the sense of is decreased.
____________________ 13. This indicates that much of what is considered taste actually depends on thesense of .
____________________ 14. It is impossible to taste substances with a tongue, because foods must be dissolved (or in solution) to excite the taste receptors.
____________________ 15. The sense of smell is closely tied to the emotional centers of the brain (limbicregion), and many odors bring back .
____________________ 16. Like the auditory receptors, the olfactory neurons tend to quickly when exposed to an unchanging stimulus (odor).
14. Figure 8-6 illustrates the site of the olfactory epithelium in the nasal cavity. Select different colors to identify the structures listed below and use them to color the coding circles and corresponding structures in the illustration. Then add a label and leader line to identify the olfactory "hairs" and add arrows to indicate the direction of impulse transmission.
⃝� Olfactory neurons (receptor cells) � Olfactory bulb
⃝� Supporting cells � Cribiform plate of the ethmoid bone
⃝� Fibers of the olfactory tract � Olfactory nerve filaments
Olfactory epithelium
Figure 8-6
At The Clinic Ch 8PLEASE DO NOT WRITE ON THIS WORKSHEET. Answer on your own paper.
1. A man in his 60’s comes to the clinic complaining of fuzzy vision. An eye examination reveals clouding of the lenses. (p 286)
a. What is his problem? b. What three factors can cause this to happen?
2. A man claiming to have difficulty seeing at night seeks help at the clinic. (p 284)a. What is the technical name for night blindness? b. What dietary supplement will be recommended? c. If the condition has progressed too far, what retinal structures will deteriorate?
3. A child is brought to the speech therapist because she does not pronounce high-pitched sounds like “s”. a. If it is determined that the source of the problem is with the hair cells of the inner ear. Which
specific region of the organ would be defective? (p 296-297)b. Is this conduction or sensorineural deafness?
4. Little Daniel’s mom tells the physician that 3-year-old Daniel has frequent earaches and that her friend told her she should have ear tubes put in his ears. The mom states that it has been a long time since Daniel had a sore throat or a cold. Upon further questioning, the mom reveals that Daniel is taking swimming lessons.
a. Does Daniel have otitis media or otitis externa? (p 291-292)b. Does he need ear tubes? Explain your reasoning. c. What is the term for cutting into (lancing) the eardrum?
5. Harry fell off a tall ladder and fractured the anterior cranial fossa of his skull. On arrival at the hospital, a watery, blood-tinged fluid was dripping from his right nostril. Several days later, Harry complained that he could no longer smell. (p 299-300)
a. What is the name of this condition, the inability to smell? b. What structures were probably damaged when the cribiform plate was fractured?
6. When Mrs. Martinez visits her ophthalmologist, she complains of pain in her right eye. The intraocular pressure of that eye is found to be abnormally elevated. (p 286)
a. What is the name of her probable condition? b. What causes it? c. What might be the outcome if the problem is not corrected?
7. Nine children attending the same daycare center developed red, inflamed eyes and eyelids. (p 279)a. What is most likely the cause of this infection of the conjunctiva? b. What is the name of this condition?c. Why will the daycare tell the parents their children will not be allowed back to the daycare for a
week?
8. Sylvia, age 70, recently underwent surgery for otosclerosis. The operation was a failure and did not improve her condition. (p 297)
a. Define otosclerosis.b. How will this condition affect the ability of her ossicles to vibrate?
9. Janie is referred to the eye clinic by her teacher, who suspects a need for glasses. Examination demonstrates Janie’s condition is myopia. (p 289)
a. Is this farsightedness or nearsightedness?b. What is wrong with the eyeball that causes this condition? c. Will she need concave or convex lenses to correct this condition?
10. An infant with strabismus is brought to the clinic. Tests show that she can control both eyes independently.
a. Describe the condition of strabismus. (p 301)b. What causes this to happen?c. What therapy will be tried before surgery?
